Underwater Flow

[Vagabond]

Anyone else here thought of taking their rudders off (assuming you are on shafts) and finishing them off nicely? Nice leading edge and sharp exit.

Most rudders I have seen are not exactly efficient in the hydrodynamic department and there are gains to be had from having a good shape as opposed to dragging some of the slabs I have seen through the water at 25 knots.

 

[oldsaltoz]

I have to agree, some of the shocking looking lumps hanging off the back of some boats make me wonder 'what were they thinking'

Avagoodweekend......

 

[Kawasaki]

in the hydrodynamic department

Any answers on here will be a waste of space from us Lads in the Nothern Hemisphere I reckon
Hydronamically of course
Doesn't the 'plug water' dissapear in the wrong direction down under?
No wonder the 'All Blacks' beat us at Rugby too.
I reckon the ball spins arese about face too!

Anyway
Rudders are made to work when needed
IE
When going slowly
Just like an English 'Scrum'
Thick at the front and thin at the back!

Tarra fer now
I,ll get me coat on an dissapear!

 

[Andrew_Fanner]

I have wondered about this on numerous occasions. Ignoring the fact that I don't think the net effect will be noticeable, what shape would you seek to achieve?

Should you use opposing aerofoils on twin rudders or a symmmetrical shape? If opposing aerofoils which side whould be high pressure and which low? Does it make a difference if the rudders are aligned with the prop shafts or not?

Thinner sctions on the trailing edge could be weaker and more prone to damage. I'm also thinking about the potential for unwanted wear on the rudder bearings caused by shake due to vortex shedding.

I'm sure its pertinent on higher performance boats than mine